Numbering system for automatic telephone exchanges



Dec. 26, 1922. 1,439,723

W. G. BLAUVELT. NUMBERING SYSTEM FOR AUTOMATIC TELEPHONE EXCHANGES.

Fl LED SEPT ORChard 5521 ORchard 5521 Orchard 5521 ACAdemy 71 28 Academy 71 28 Academy 71 28 CQRfland 9432 COrtIand 9452 Cortland 9452 DECatur 861 2 DEcatur 861 Z Decatur 861 2 [A51 n.y. 5555 EA9 n.y. 5555 E551 my. 5555 JAMaica 9210 JAmaica 9210 Jamaica 9210 MORn1ngside336l Morningside' 3361 Morningside 3361 C101 1957 or I 1987 R5551 I98? SEAm 5215 SEaford 5215 Seaford 621 5 WOR1h 4121 W015 4121 Worth 4121 IN V EN TOR.

Patented Dec. 26, 1922.

UNITED STATES PATENT OFFICE.

WILLIAM G. BLAUVELT, OF NEW YORK, N. Y., ASSIGNOR TO AMERICAN TELEPHONE AND TELEGRAPH COMPANY, A CORPORATION OF NEW YORK,

NUMIBERING SYSTEM FOR AUTOMATIC TELEPHONE EXCHANGES.

Application filed September 17, 1918 Serial No. 254,464.

To all whom it may concern Be it known that I, WILLIAM G. BLAU- .VELT, residing at New York, in the county of New York and State of New York, have invented certain Improvements in Numbering Systems for Automatic Telephone Exchanges, of which the following is a specification.

This invention relates to the art of teleph ony and more particularly to telephone systems in which subscribers are connected by means of automatic switching machinery.

Heretofore it has been customary to designate subscribers by means of a number which is listed in the directory opposite the subscribers name so that any one desiring to call a particular subscriber may call his number instead of his name. Where the number of subscribers lines is 10,000 or over, it has been deemed inexpedient to follow this practice inasmuch as each subscribers number would then involve five digits or over, so that the liability of error due to the subscriber or operator forgetting the number is greatly increased.

Where such a large number of subscribers is involved it has been customary to divide the subscribers lines into different groups terminating at different central offices, con-r nections between subscribers of different offices being established by a system of inter-office trunking. By keeping the number of lines terminating at a given oflice below 10,000, it is possible to designate each subscriber in the directory by the office name followed by the number of his line in that office. In this case it is only necessary to remember a name and a number of not more than four digits.

lVhe-re connections are established by means of switching machinery under the control of a sender manipulated by the subscriber this scheme is no longer feasible for the reason thatthe sender in all practical cases is an arrangement such as a dial provided with ten calling positions representing the ten fundamental digits of the Arabic system of notation. In this case, in order to avoid numbers of more than four digits, it has been proposed that each calling position of the dial be designated by a letter in addition to a digit, and in place of the office name in the directory a combination of one or more letters be substituted.

The calling subscriber will then dial the letters' of the called s ubscribers designation in the same manner as the digits comprising the number.

This scheme involves a number of disadvantages in that it requires each subscriber to be listed by two designations in the directory of a locality employing both manual and automatic switching, and furthermore where three letters or more are used in addition to the four digits comp-rising'the subscribers number, the liability of errors due to the difficulty of memorizingthe subscribers designation, is increased.

It is one of the principal objects of this invention to overcome the difficulties above mentioned, although other and further objects will be clear from'the detailed description hereinafter appearing.

In carrying out the objects of this inveni tion it is contemplated that each position of the dial be designated by one or more letters, these letters being so chosen that combinations of letters may be made up therefrom which are suggestive ofthe ofli'cename which in manual practice forms a part ofthe 'subscribers designation. These combinations of letters may then be printed in the directory in a manner distinguishing them from the other letters making up the office names, so that a subscriber desiring to complete a connection automatically may readily observe and memorize as the called subscribers desi nation the distinctive 'combination of letters and the associated number. At-the'same time the subscribers whose lines terminate in manual and semi-mechanical offices may repeat to the operator the office name and associated number as in the usual manual practice. In the case of the semi-mechanical ofiice the operator may actuate her sender by registering letters instead of office names as is now. the practice.

The invention may now be more fully understood from the following description when readin connection with the accompanying drawing, Figure l of'which is a schematic representation of a subscribers dial suitable for use in establishing connections in accordance with the method of this invention. while Figs, 2', 3 and 4 illustrate three different ways of designating the subscribers in the directory.

Referring to Fig. l, a. dial 20 is shown pivoted at 21and provided with a series of finger holes about its periphery, said. finger holes being designated by the ten Arabic digits, and also by ten letters of the alphabet. In the particular case illustrated the letters 0, A, b, D, E, J, M, R, S, and W are employed, but it will be understood that letters other than those illustrated may be employed, the essential requirement being that the letters be so chosen that a large number of combinations suggestive of oflice names, may be made up therefrom. When ten letters are insufficient to provide the necessary number of combinations each finger hole may, if desired, be designated by two letters and one numeral, so that twenty letters-of the alphabet will be available, thus allowing a greater latitude in the office names employed. In operating the dial 20 the calling subscriber, having first memorized the designation of the called subscriber, which will consist of a combination of letters representing the office and a combination of digits representing the number' of the called subscribers line at that office, will insert his finger in the hole corresponding to the first letter of the called subscribers designation and pull the dial in a clockwise direction until his finger engages with the stop 22, whereupon he releases the dial and permits it to be restored to normal. In the same manner he dials the succeeding letters, if any, together with the associated number in regular order. This operation, results in the completion of a connection with the called subscriber bv means of switching machinery in a well known manner.

To assist the calling subscriber in memorizing the called subscribers designation,

' the designations will comprise an office name and a line number printed in the directory in accordance with the usual manual practice, except that one or more letters of the office name which are suggestive thereof will be printed in such a way as to distinguish them from the other letters of the oflice name. For instance in large communities, the first three letters or a combination of letters of the office name may be printed in capitals and the remaining letters printed in small type as shown in Fig. 2. A subscriber desiring to call by means of his dial RECtor 1987 will successively dial the letters R. E. C. followed by the digits, 1, 9, 8, 7. .This is equivalent to dialing a subscriber whose number is 7421987. A comparison of these two designations shows at once the advantages of the present system. Not only is the subscribers designation easier to memorize, but in addition. the same designation may be used for either manual or full automatic switching, thus avoiding printing two subscribers designations in the directory of a community where both switching systems are employed. It for automatic calling the first name be replaced by three arbitrarily chosen letters, as

has heretofore been the practice, not only will the combination be difficult to memorize, but, owing to the difficulties of enunciation, it will be necessary to give the subscriber an additional designation involving an office name instead of a group of letters for the use of subscribers whose lines terminate at manual exchanges. It will be understood of course that when an operator completes a connection by means of a sending. arrangement under her control, the sender maybe actuated by registering combinations of letters and numerals as occurring inthe directory instead of registering an ofiice name and number.

In smaller communities it will only be necessary to use the first two letters of the office name in dialing, as shown in Fig. 3, since two letters and four figures will give a sufficiently large number of combinations. In still smaller communities, involving not over ten exchanges, only the first letter of the office named need be used in dialing as shown in Fig. 4.

\Vhen it is realized that it has heretofore been impractical to establish connections between subscribers in extremely large communities by means of the full automatic method, by reason of the difficulties involved in designating the subscribers by numbers involving a large number of digits or by combinations of arbitrarily chosen letters and numbers, the advantages of the present invention may be more fully realized.

By means of the present invention it is possible to use full automatic machine switching systems in communities having several hundred offices of approximately 10,000 lines each, which is well above the re quirements of the largest communities now in existence.

It will also be obvious that the general principles herein disclosed may be embodied in many other systems and organizations widely different from those illustrated and described without departing from the spirit of the invention as defined in the following claims.

\Vhat is claimed is:

1. The method of dialing in a mechanical switching system in which subscribers are designated by a combination of office names and numbers, which consists in assigning names to the offices of the system each having a characteristic letter which is different for each office dialing the letter of the office name which is suggestive thereof to establish aconnection to a desired office. and then successively dialing the digits of the number of the subscribers designation to establish a connection to a subscriber in the office.

office.

designated by a combination of office names and numbers, which consists in dialing in succession a plurality of letters of the office name which are suggesive thereof to estab lish a connection to a desired office, and then successively dialing the digits of the number of the subscribers designation to establish a connect-ion to a subscriber; in the office.

3. The method of dialing in amechanical switching system in which subscribers are designated by a combination of office names and numbers, which consists indialing in succession a combination of letters of the office name to establish a. connection to a desired office and then dialing the digits of the number of the subscribers designation to establish a connection to a subscriber in the office.

4. The method of directively operating switches to establish a. connection in a mechanical switching system in which sub-- scribers are designated by a combination of office names and numbers, and in which the switches are operated in response to the transmission of varied each group of impulses representing either a letter or a digit, which consists in assigning names to the offices of the system each having a characteristic letter which is different for each office transmitting a group of impulses corresponding to a letter of the office name which is suggestive thereof to establish a connection to a. desired office. and then transmitting successive groups of impulses corresponding to the digits of the number of the subscribers designation to establish a connection to a subscriber in the office.

The method of directively operating switches to establish a connection in a. mechanical switching system in which subscribers are designated by a combination of office names and numbers. and in which the switches are operated in response to the transmission of varied groups of impulses each group of impulses representing either a letter or a digit, which consists in transmitting a succession of groups of impulses corresponding to a plurality of letters of the office name which are suggestive thereof to establish a connection to a desired office, and then transmitting successive groups of impulses corresponding to the digits of the numbei of the subscribers designation to establish a connection to a subscriber in the 6. The method of diiectively operating switches to establish a. connection in a mechanical switching system in which subscribers are designated by a. combination of office names and numbers, and in which the switches are operated in response to the groups of impulses,

transmission of varied groups ofimpulses, each group of impulses representing either a' letter or a digit, which consists in trans mitting a succession of groups of impulses corresponding to a combination of letters of the office name to establish. a connection to a desired office, and thentransmitting successive groups of impulses corresponding to the digits of the number of the subscribers designation toestablish a connection to a subscriber in the office.

7. A code for designating telephone subscribers in a system in which subscribers lines are grouped so that lines of different groups terminate in different offices between which trunk connections may be established, said code comprising a combination of the ofiice name and the number of the subscribers lines in said office, at least one of the letters of the office name which are suggestive thereof being represented in a manner characteristically different from the manner in which the other letters are represented, so that subscribers desiring manual connections may call the office name and number of the subscriber, and subscribers requiring to establish mechanically switched connections may dial the characteristic letter of the name and the digits of the number of the subscribers designation.

8. A code for designating telephone subscribers in a system in which subscribers lines are grouped so that lines of different groups terminate in different offices between which trunk connections may be established, said code comprising a combination of the office name and the number of the subscribers line in said ofiice, certain of the letters of the office name which are suggestive thereof being represented in a manner characteristically different from the manner in which the other letters are represented, so that subscribers desiring manual connections may call the oflice name and number of the subscriber, and subscribers requiring to establish mechanically switched connections may dial the characteristic letare represented, so that subscribers desiring manual connections may call the office name and number of the subscriber, and subscribers requiring to establish mechanically machinery under the control of dials, which consists in applying letters to the dial so that at least one letter is correlated with each of a group of numerals on the dial, and adopting a word name for each office, said word name being made up of letters, at least one of which is characteristic of the name and is dialed for controlling connections to that oilice, said names being so chosen that difi'erent characteristic letters appear in each name.

11. The method of designating telephone subscribers in a system in which subscribers lines are grouped so that lines of different groups terminate in difl'erent offices, between which trunk connections may be established, and in which said trunk connections may be established through switching machinery under the control of dials, which consists in applying letters to the dial so that at least one letter is correlated with each of a group of numerals on the dial, and adopting a word name for each oflice, said word name being made up of letters, a plurality of which are dialed in sequence for controlling connections to that ofiice.

'12. The method of designating telephone subscribers in a system in which subscribers lines are grouped so that lines of different groups terminate in different offices, between which trunk connections may he established, and in which said trunk connections may be established through switching machinery under the control of dials, which consists in applying letters to the. dial so that at least one letter is correlated with each of a group of numerals on the dial, and adopting a word name for each oiiice, said word name being made up of letters, a combination of which is dialed for controlling connections to that oiiice.

In testimony whereof I have signed my named to this specification this thirteenth day of Sept, 1918.

WILLIAM G. BLAUVELT. 

